Floor underlayment



FIG. 1 is a top perspective view of a floor underlayment, showing my new design;

FIG. 2 is a side elevational view thereof, the other sides being identical thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof, opposite that of FIG. 3;

FIG. 5 is a bottom perspective view thereof, opposite that of FIG. 1;

FIG. 6 is a top perspective view of a second embodiment of a floor underlayment, showing my new design;

FIG. 7 is a side elevational view of the embodiment of FIG. 6, the other sides being identical thereof;

FIG. 8 is a top plan view of the embodiment of FIG. 6;

FIG. 9 is a bottom plan view of the embodiment of FIG. 6, opposite that of FIG. 8; and,

FIG. 10 is a bottom perspective view of the embodiment of FIG. 6, opposite that of FIG. 6. 

CLAIM The ornamental design for a floor underlayment, as shown and described. 